In an LTE network, packet switched roaming is arranged to work such that both signalling and media traffic are routed back to the home network regardless of the destination of the call. Thus a voice call over the LTE packet switched network domain using the home routing model does not work properly, due to the too much increase of delay between the foreign roaming network and the home network.
One solution is to continue using the 2/3G network instead of LTE whenever a user terminal is roaming. A disadvantage with that is that advanced LTE services (other than voice) would then not work during roaming. Another solution may be to use manual network selection from LTE to 2/3G prior to making a voice call. A disadvantage associated with that is that the user of the user terminal is not necessarily aware of the available 2/3G networks, if any, to make the selection.